Arduino + Led + Touchdesigner

Hello,
I'm a beginner with arduino an Touchdedsigner, I just managed to make a Interface with Touchdesigner and there is a button, which should turn on/off the LED (connected with Arduino). Can someone tell me how I can do that?

Thanks
Heliya

What is Touchdesigner? Can it send serial output?

Hi again.
Yup:

send /project1/serial1 "ABC"

for example.

(TouchDesigner is a realtime visual software package we develop at derivative.ca)

Cheers,
Rob.